Identification of HAVCR1 gene haplotypes associated with mRNA expression levels and susceptibility to autoimmune diseases

Human HAVCR1 gene maps on 5q33.2, a region linked with susceptibility to allergic and autoimmune diseases. The aims of the present study were to define the haplotypes of HAVCR1 gene taking into account both HapMap Project SNP haplotypes and exon 4 variants, to investigate a possible relationship between these haplotypes and mRNA expression levels, and to assess whether HAVCR1 gene is involved in susceptibility to rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Genotyping of three ins/del variants in the exon 4 was performed by fragment length analysis. Five tag SNPs genotypes and mRNA levels were determined using TaqMan assays. We defined four major haplotypes in our population: the two major haplotypes (named haplotypes A and B) bear both the 5383_5397del variant and the two most common SNP sets found in the CEU population. Quantification analysis revealed that genotype B/B had the highest median of mRNA expression levels (vs. BX + XX, p < 0.0001). Additionally, frequency of the genotype BB was significantly higher in RA patients than in controls (12.3 vs. 5.9% in controls, p = 0.0046, p _c = 0.014, OR = 2.23, 95% CI 1.23–4.10). Our results support a relationship between HAVCR1 haplotypes and mRNA expression levels, and suggest an association of this gene with autoimmune diseases.     

Model of chromosome associations in Mus domesticus spermatocytes

Understanding the spatial organization of the chromosomes in meiotic nuclei is crucial to our knowledge of the genome's functional regulation, stability and evolution. This study examined the nuclear architecture of Mus domesticus 2n=40 pachytene spermatocytes, analyzing the associations among autosomal bivalents via their Centromere Telomere Complexes (CTC). The study developed a nuclear model in which each CTC was represented as a 3D computer object. The probability of a given combination of associations among CTC was estimated by simulating a random distribution of 19 indistinguishable CTC over n indistinguishable "cells" on the nuclear envelope. The estimated association frequencies resulting from this numerical approach were similar to those obtained by quantifying actual associations in pachytene spermatocyte spreads. The nuclear localization and associations of CTC through the meiotic prophase in well-preserved nuclei were also analyzed. We concluded that throughout the meiotic prophase: 1) the CTC of autosomal bivalents are not randomly distributed in the nuclear space; 2) the CTC associate amongst themselves, probably at random, over a small surface of the nuclear envelope, at the beginning of the meiotic prophase; 3) the initial aggregation of centromere regions occurring in lepto-zygotene likely resolves into several smaller aggregates according to patterns of preferential partitioning; 4) these smaller aggregates spread over the inner face of the nuclear envelope, remaining stable until advanced stages of the meiotic prophase or even until the first meiotic division.     

Seedling dynamics at elevation limits: Complex interactions beyond seed and microsite limitations

? Premise of the study: Limited availability of seeds and microsites are important constraints for seedling emergence and survival. However, little is known about population-level feedbacks between seed and microsite limitation and how these relationships vary in contrasting conditions. Focusing on Armeria caespitosa, a high-mountain endemic, we asked whether seedling establishment was simultaneously limited by seed and microsite availability, whether the balance between seed and microsite limitations varied with contrasting environments, and whether seed and microsite limitations interacted with each other. ? Methods: We studied seedling emergence and survival at the edges of the elevation range of A. caespitosa in central Spain over 4 years. We used mixed linear models and structural equation modeling. ? Key results: Our results showed that A. caespitosa recruits similar numbers of new seedlings per plot in contrasting environments. Seedling emergence and survival in A. caespitosa were both limited by seed and microsite availability. Habitat suitability (the surrogate of microsite limitation) varied between populations and indirectly affected fertility (the surrogate of seed limitation). ? Conclusions: Seedling emergence and survival are both seed and microsite limited, there are interactions between seed and microsite limitations, and both factors, which control seedling establishment, and their interconnections, vary among local populations.     

Celastrol suppresses IFN-gamma-induced ICAM-1 expression and subsequent monocyte adhesiveness via the induction of heme oxygenase-1 in the HaCaT cells

Celastrol, a quinone methide triterpenoid derived from the medicinal plant Tripterygium wilfordii, possesses various biological activities such as anti-oxidant, anti-tumor, and anti-inflammatory activities. In this study, we examined the suppressive effect of celastrol on IFN-γ-induced expression of ICAM-1 and the molecular mechanism responsible for these activities. We found that celastrol induced mRNA and protein expression of heme oxygenase-1 (HO-1) in the human keratinocyte cell line HaCaT. Treatment of HaCaT cells with tin protoporphyrin IX (SnPP), a specific inhibitor of HO-1, reversed the suppressive effect of celastrol on IFN-γ-induced protein and mRNA expression of ICAM-1. HO-1 knockdown using small interfering RNA (siRNA) led to reverse inhibition of IFN-γ-induced up-regulation of ICAM-1 by celastrol. In addition, SnPP reversed suppression of IFN-γ-induced promoter activity of ICAM-1 by celastrol. Furthermore, blockage of HO-1 activity by SnPP and HO-1 siRNA reversed the inhibitory effect of celastrol on IFN-γ-induced adhesion of monocytes to keratinocytes. These results suggest that celastrol may exert anti-inflammatory responses by suppressing IFN-γ-induced expression of ICAM-1 and subsequent monocyte adhesion via expression of HO-1 in the keratinocytes.     

Effects of antioxidants on post-thawed bovine sperm and oxidative stress parameters: Antioxidants protect DNA integrity against cryodamage

This study was conducted to determine the effects of methionine, inositol and carnitine on sperm (motility, abnormality, DNA integrity and in vivo fertility) and oxidative stress parameters (lipid peroxidation, total glutathione and antioxidant potential levels) of bovine semen after the freeze–thawing process. Nine ejaculates, collected with the aid of an artificial vagina twice a week from each Simmental bovine, were included in the study. Each ejaculate, splitted into seven equal groups and diluted in Tris-based extender containing methionine (2.5 and 7.5 mM), carnitine (2.5 and 7.5 mM), inositol (2.5 and 7.5 mM) and no additive (control), was cooled to 5 °C and then frozen in 0.25 ml straws. Frozen straws were then thawed individually at 37 °C for 20 s in a water bath for the evaluation.The extender supplemented with 7.5 mM doses of carnitine and inositol led to higher subjective motility percentages (61.9 ± 1.3% and 51.3 ± 1.6%) compared to the other groups. The addition of methionine and carnitine at doses of 2.5 and 7.5 mM and inositol at doses of 7.5 mM provided a greater protective effect in the percentages of total abnormality in comparison to the control and inositol 2.5 mM (P < 0.001). As regards CASA motility, 7.5 mM carnitine (41.6 ± 2.9% and 54.2 ± 4.9%) and inositol (34.9 ± 2.0% and 47.3 ± 2.2%) caused insignificant increases in CASA and total motility in comparison to the other groups. All of the antioxidants at 2.5 and 7.5 mM resulted in lower sperm with damaged DNA than that of control, thus reducing the DNA damage (P < 0.05). No significant differences were observed in CASA progressive motility and sperm motion characteristics among the groups. In fertility results based on 59-day non-returns, no significant differences were observed in non-return rates among groups. As regards biochemical parameters, supplementation with antioxidants did not significantly affect LPO and total GSH levels in comparison to the control group (P > 0.05). The maintenance of AOP level in methionine 2.5 mM was demonstrated to be higher (5.06 ± 0.38 mM) than that of control (0.96 ± 0.29 mM) following the freeze–thawing (P < 0.001). Supplementation with these antioxidants prior to the cryopreservation process protected the DNA integrity against the cryodamage. Furthermore, future research should focus on the molecular mechanisms of the antioxidative effects of the antioxidants methionine, carnitine and inositol during cryopreservation.     

Strains nodulating Lupinus albus on different continents belong to several new chromosomal and symbiotic lineages within Bradyrhizobium

In this work we analysed different chromosomal and symbiotic markers in rhizobial strains nodulating Lupinus albus (white lupin) in several continents. Collectively the analysis of their rrs and atpD genes, and 16S-23S intergenic spacers (ITS), showed that they belong to at least four chromosomal lineages within the genus Bradyrhizobium. Most isolates from the Canary Islands (near to the African continent) grouped with some strains isolated on mainland Spain and were identified as Bradyrhizobium canariense. These strains are divided into two ITS subgroups coincident with those previously described from isolates nodulating Ornithopus. The remaining strains isolated on mainland Spain grouped with most isolates from Chile (American continent) forming a new lineage related to Bradyrhizobium japonicum. The strains BLUT2 and ISLU207 isolated from the Canary Islands and Chile, respectively, formed two new lineages phylogenetically close to different species of Bradyrhizobium depending on the marker analyzed. The analysis of the nodC gene showed that all strains nodulating L. albus belong to the biovar genistearum; nevertheless they form four different nodC lineages of which lineage C is at present exclusively formed by L. albus endosymbionts isolated from different continents.     

Dasyatispora levantinae gen. et sp. nov., a new microsporidian parasite from the common stingray Dasyatis pastinaca in the eastern Mediterranean

A new microsporidian infecting the Mediterranean common stingray Dasyatis pastinaca (Linnaeus, 1758) is described from Iskenderun Bay, Turkey. The parasite invades the disc muscles, producing slender, spindle-shaped subcutaneous swellings that develop into massive, elongated, tumor-like protuberances measuring up to 11 x 4 cm. Severity of the infection may vary from light (1 or 2 small lesions) to intense, with large parts of the dorsal surface covered with lumps and protrusions. These masses contained a yellowish-white caseous substance consisting of degraded host tissue and microsporidian sporophorous vesicles, which in turn contained developing sporonts, sporoblasts and spores. The ripe spore contained a uni-nucleate sporoplasm and large posterior vacuole, and measured 3.8-4.3 x 2.6-2.8 microm. Infection prevalence was 21% in a sample of 143 host individuals examined. All the infected stingray individuals were within the weight class of 300 to 800 g (200 to 305 mm disc width). Phylogenetic analyses of rDNA sequences indicate that this microsporidian belongs to the Pleistophoridae and clusters with species of the genera Ovipleistophora Pekkarinen, Lom & Nilsen, 2002 and Heterosporis Schubert, 1969. However, the morphology, development and host differ distinctly from all reported species, including those belonging to these 2 genera, and it is thus assigned to a newly erected genus and named Dasyatispora levantinae gen. et sp. nov. This is the first record of a microsporidian infection in a batoid. It is also the first microsporidian species to be formally described from an elasmobranch.     

Visfatin stimulates proliferation of MCF-7 human breast cancer cells

Obesity, a condition characterized by increased fat content and altered secretion of adipokines, is a risk factor for postmenopausal breast cancer. Visfatin has recently been established as a novel adipokine that is highly enriched in visceral fat. Here we report that visfatin regulated proliferation of MCF-7 human breast cancer cells. Exogenous administration of recombinant visfatin increased cell proliferation and DNA synthesis rate in MCF-7 cells. Furthermore, visfatin activated G1-S phase cell cycle progression by upregulation of cyclin D1 and cdk2 expression. Visfatin also increased the expression of matrix metalloproteinases 2, matrix metalloproteinases 9, and vascular endothelial growth factor genes, suggesting that it may function in metastasis and angiogenesis of breast cancer. Taken together, these findings suggest that visfatin plays an important role in breast cancer progression.     

Auditory evoked blink reflex and posterior auricular muscle response: Observations in patients with HFS and PFS

Our goal was to investigate the characteristics of the auditory brainstem reflexes in patients with hemifacial spasm (HFS) and postparalytic facial syndrome (PFS).The spasm activities and responses by supraorbital and auditory stimuli were recorded from the orbicularis oculi, the posterior auricular and the mentalis muscles in 27 HFS and 21 PFS patients. The results were compared with those of 20 controls.Blink reflex (BR) was obtained by supraorbital stimulation in normal controls and on both sides of HFS and PFS patients whereas sound evoked bilateral auditory blink reflex (ABR) in 96.3%, 90.5% and 100%, respectively. Both BR and ABR showed synkinetic spread on symptomatic sides in all patients. The posterior auricular muscle response (PAMR) was observed bilaterally in 59.3%, 42.9% and 75.0% of groups, respectively. However, there was no synkinetic spread of PAMR.Since PAMR does not show synkinetic spread even in the presence of synkinetic spread of ABR and BR, we may suggest that a distal origin may be responsible of the synkinetic spread, or PAM is probably governed by a smaller nucleus in the brainstem. Thus it may be speculated that its excitability is insufficient to stimulate the ABR nucleus, whereas the reverse process is possible.